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Dry Store Room No. 1: The Secret Life of the Natural History Museum - Richard Fortey

Alan showed me one mineral that could not be displayed at all to common view. Proustite has a blood-red colour that fades when exposed to light – a shy creature, indeed. It was not named after the novelist Marcel Proust, though one feels it should have been. These famous, well-formed crystals mined from Copiapo, Chile, some of which would almost cover your hand, have an unreal quality, as if they did not quite belong on this Earth at all. I suppose that since they are a compound of silver, arsenic and sulphur they must also be very poisonous. They thus combine a lethal but hidden beauty; they are of the earth, but somehow also unearthly. Wordsworth was no friend of geologists, whom he regarded as dull enumerators of facts, but he did write a line that seems quite appropriate to gemstones: ‘True beauty lies in deep retreats.’ 

I thought I'd share this part because the mineral is just beautiful: